This disclosure is generally directed to an imaging member comprising a supporting substrate, an optional hole blocking layer, an optional adhesive layer, an imaging layer such as separate or combined charge generating layer and charge transport layer, and an overcoat layer comprising a fluorosulfonamide and optionally a charge transport compound and a melamine resin.
In electrophotography, also known as Xerography, electrophotographic imaging or elecrostatographic imaging, the surface of an electrophotographic plate, drum, belt or the like (imaging member or photoreceptor) containing a photoconductive insulating layer on a conductive layer is first uniformaly electrosatically charged. The imaging member is then exposed to a pattern of activating electromagnetic radiation, such as light. The radiation selectively dissipates the charge on the illuminated areas of the photoconductive insulating layer while leaving behind an electrostatic latent image on the non-illuminated areas. This electrostatic latent image may then be developed to form a visible image by depositing finely divided electroscopic making particle son the surface of the photoconductive insulating layer. The resulting visible image may then be transferred from the imaging member directly or indirectly (such as by a transfer or other member) to a print substrate, such as transparency or paper. The imaging process may be repeated many times with reusable imaging members.
Although excellent toner images may be obtained with multilayered belt or drum photoreceptors, it has been found that as more advanced, higher speed electrophotographic copiers, duplicators, and printers are developed, there is a greater demand on print quality. The delicate balance in charging image and bias potentials, and characteristics of the toner and/or developer, must be maintained. This places additional constraints on the quality of imaging member manufacturing, and thus on the manufacturing yield.
Imaging members are generally exposed to repetitive electrophotographic cycling, which subjects the exposed charged transport layer or alternative top layer thereof to mechanical abrasion, chemical attack and heat. This repetitive cycling leads to gradual deterioration in the mechanical and electrical characteristics of the exposed charge transport layer. Physical and mechanical damage during prolonged use, especially the formation of surface scratch defects, is among the chief reasons for the failure of belt photoreceptors. Therefore, it is desirable to improve the mechanical robustness of photoreceptors, and particularly, to increase their scratch resistance, thereby prolonging their service life. Additionally, it is desirable to increase resistance to light shock so that image ghosting, background shading, and the like is minimized in prints.
Long life imaging members enable a significant run-cost reduction. Providing a protective overcoat layer is a conventional means of extending the useful life of imaging members. Such conventional approaches to extend the life include applying an overcoat layer with wear resistance. While this approach works for scorotron charging systems, it suffers drawbacks in other systems, such as where there is a trade-off between image quality, imaging member lifetime, and wear rate.
Despite the various approaches that have been taken for forming imaging members, there remains a need for improved imaging member design, to provide improved imaging performance and longer lifetime, reduced torque, reduced human and environmental health risks, and the like. These and other needs are believed to be achievable with the imaging members disclosed herein.